Carolina Parakeet Tasmanian Tiger Gastric brooding frog

Transcription

Carolina Parakeet Tasmanian Tiger Gastric brooding frog
Carolina Parakeet
Panthera leo barbaricus
Barbary Lion
extinct around
1935? (1918?)
Extinct 1922
Tasmanian Tiger
Gastric brooding frog
•
•
Extinct 1936
Extinct ?
Not found since
1985
Table 2.2. A sample of species once thought extinct, but rediscovered.
Species name
Common name
Date
# yrs since
rediscovered
last sighting
Dipsochelys hololissa
Seychelles giant tortoise
1997
>150
Pterodroma cahow
Bermuda petrel
1951
>300
Perameles bougainville
Western barred bandicoot
1983
61
Trichocichla rufa
Long-legged warbler
2003
109
Gastrolobium lehmannii
Cranbrook pea
2001
83
Hapalopsittaca fuertesi
Fuertes's parrot
2002
91
Hypsiprimnus gilbertii
Gilbert’s potoroo
1994
85
Sida inflexa
Virginia pine sida
1999
31
Lepidoptrix (formerly Pipra) vilaboasi
Golden crowned manakin
2002
45
Such disappearances and reappearances are common. Keith and Burgman (Keith and
Aldabra tortoise
Seychelle tortoise
Burgman 2004) examined lists of extinct plants in Australia and found that, of 113 species listed
as extinct in 1981, only 61 species remained on the extinct list twenty years later. Species were
dropped from the extinct list for a variety of reasons including taxonomic revisions, but the most
common reason was the rediscovery of remnant individuals. Keith and Burgman humorously
named this phenomenon of species reappearing after their supposed extinction the Lazarus
effect. Even more surprising than the frequent rediscovery of extinct species is that the majority
http://members.aol.com/jstgerlach/tortoise.htm
Seychelle saddleback
ns with higher spending for biodiversity monitoring, large-bodied species are occasionally
covered (Box 2.2).
2.2. Rediscovery of the Ivory-Billed Woodpecker
Measuring Current Extinctions
It has been described as the “Lord-God” bird and “the
grail of birding”. The ivory-billed woodpecker is among the
’s largest woodpecker species. A one-time denizen of the
mps and bayous of the southeastern US, this spectacular bird
Direct observation are difficult
Indirect observation: species - area relationship
n unfortunate victim of habitat destruction, as the birds’
mpy habitats were extensively logged and drained during the
1900’s to make way for farms. (Artistic rendition of the
-billed woodpecker courtesy of Mark Bowers http://nc-
s.gov/birds/ivorybill.html). The last individual to be documented in the United States, an
red female, was spotted in 1944. It was later assumed that the Ivory-billed woodpecker had
mbed to extinction, joining five other North American bird species thought to have become
ct since 1880: the Labrador duck (Camptorhynchus labradorius), Eskimo curlew (Numenius
lis), Carolina parakeet (Conuropsis carolinensis), passenger pigeon (Ectopistes
atorius), and Bachman's warbler (Vermivora bachmanii).
In February 2004, a kayaker paddling through the Cache River National Wildlife Refuge
Species-Area relationship
ntral Arkansas spotted an unusually large woodpecker with markings resembling those of
Species-Area relationship
ory-bill. Word of his sighting spread and aroused the curiosity of leading bird experts.
S = c × Az
S = c × Az
after, additional sightings were made and expeditions were organized by scientists from
izations including the Cornell Lab of Ornithology and The Nature
Number
of species S
c is a taxon specific constant
z is the extinction coefficient
Conservancy.
is in the range In
0.1 to 0.3
on to extensive searching, the researchers set out arrays of remote cameras and sound
c is a taxon specific constant
z is estimated using the slope
log(Number
of species S)
Chapter 2 – Page 19
Area A
log(Area A)
Mac Arthur and Wilson (1967):
the theory of island biogeography
Fig 4.5
Small mammals in forest
granivores
all small mammals
r2 = proportion of variation explained
Estimating extinction rates
Estimating how many species go extinct
Snow
Log(Number
of species S)
Soriginal
Log(Area A)
Snow
Soriginal
cAznow
=
cAzoriginal
=
Aznow
Azoriginal
Snow = Soriginal
Log(Number
of species S)
Aznow
Azoriginal
Log(Area A)
using
z=.15 (this is arbitrary)
deforestation = 1.8% per year (Anow / Aoriginal = 98.2/100)
10 million species (Soriginal)
Snow = 9,973,000
Difference between Snow and Soriginal = 27,000 species per year
Causes of extinction?
88
46
20
14
Disease
Overharvest
Pollution
Exotic
species
2
Habitat
destruction
and
degradation
Percent of species affected
Causes of endangerment
100
90
80
70
60
50
40
30
20
10
0
Causes of extinction
88
46
20
Habitat destruction
14
Disease
Overharvest
Pollution
Exotic
species
2
Habitat
destruction
and
degradation
Percent of species affected
Causes of endangerment
100
90
80
70
60
50
40
30
20
10
0
habitat loss (less area = fewer species)
Causes of extinction
Habitat destruction
habitat loss (less area = fewer species)
habitat fragmentation
Fringed prairie orchid
Causes of extinction
Fig 55.6
Forest cover of
Cadiz Township in
Wisconsin
Habitat destruction
habitat loss (less area = fewer species)
habitat fragmentation
Edge effects
Fragmentation
Fig 4.5
Small mammals in forest
granivores
all small mammals
r2 = proportion of variation explained
Causes of extinction
Habitat destruction
Habitat loss (less area = fewer species)
Habitat fragmentation
Edge effects
Isolation
Exotic species
88
Exotic species: species introduced to regions outside of their
native range
46
20
14
Invasive species: an exotic species with strongly increasing
populations (and most often detrimental effect on the
native species or habitats)
Disease
Overharvest
Pollution
Exotic
species
2
Habitat
destruction
and
degradation
Percent of species affected
Causes of endangerment
100
90
80
70
60
50
40
30
20
10
0
Exotic species
Invasive species
Brown tree snake
Kudzu
Introduced to Guam,
predated and eradicated
all native endemic bird
species
Introduced to the SouthEast USA for their edible
leaves and pretty flowers.
Overgrowing forests,
changing native habitats
Zebra mussel
Introduced through boats into
Great Lakes, clogging up water
intakes, removing food more
effective out of water column
than natives.
Pollution
Point sources
88
Non-Point sources
46
20
14
Disease
Overharvest
Exotic
species
Pollution
2
Habitat
destruction
and
degradation
Percent of species affected
Causes of endangerment
100
90
80
70
60
50
40
30
20
10
0
Pollution
Pollution
Air
Water
Global warming
Acid rain
Ozone depletion, smog, ....
Pollution
Heavy metal
Water Body
Species
Women of
childbearing age,
young children
One per month
All Other Individuals
(# of meals)*
Lake Iamonia
Largemouth Bass
!Lake Jackson
Black Crappie,
Bluegill, Largemouth
Bass
Bluegill
Largemouth Bass
One per month
One per week
Two per week
One per month
Two per week
One per week
Lake Munson
Black Crappie, Redear One per month
Sunfish
One per week
Moore Lake
Largemouth Bass
One per week
Lake Miccosukee
http://www.myfloridaeh.com/community/fishconsumptionadvisories/FWFGuide.htm
One per month
One per week
Water
Toxins
Nutrients
eutrophic vs oligotrophic
PRESS RELEASE, JULY 26, 2004
LOUISIANA UNIVERSITIES MARINE CONSORTIUM
AVERAGE SIZE "DEAD ZONE" IN ANYTHING BUT AN AVERAGE YEAR
The coast-wide extent of the Louisiana "dead zone" mapped this week is slightly larger than average at 15,040 km2 (5,800 square miles). The long-term
average since mapping began in 1985 is 13,000 km2 (5,000 square miles). The river flow and the offshore conditions prior to the mapping cruise were
anything but normal and were more reminiscent of the Great Mississippi River Flood of 1993. The river in 2004 peaked in discharge several times in January,
February, March and May, followed by a prolonged above average flow that persisted from June into July, as in 1993.
Exploitation
Commercial
Incidental Exploitation
Bycatch: albatross, whales, ....
Predator control in parks
Recreation
Pets
Recreational
Diseases
Causes of extinction
(Atelopus zeteki)
Habitat destruction
Chytrid, a fungus, is
believed to be one of
the sources for
amphibian decline
Exotic species
Pollution
Exploitation
www.clemetzoo.com/conservation/project_golden_frog.asp
Diseases